In general terms of designing an exhaust system the following
basic guidelines are used.
The largest muffler should be in the rear because it will make
the system less loud. If you only use one muffler it should be
in the rear. For a 150 hp/2 valve engine there are no gains
by using a 2.5 inch pipe size except noise. After the exhaust
manifold header, use a short piece of 2 inch pipe (4-6 inches)
and go up to 2.25 inch if you want to use the 2.25 inch pipes.
Use the largest straight through design muffler you can fit. A
Flowmaster is not a straight through design. If you are using
2 mufflers they should be different in size and/or shape.
Larger diameter pipes gives a deeper exhaust note. Some
like to use 2.5 inch pipes anyway but instead the mufflers
are reduced to 2 inches inside to cut down on the noise.
The end tip should not end before the rear bumper or it will
make more noise inside the car.
There basic guidelines are correct in 95% of all applications.
Thomas
Kyle Hagemann wrote:
> Hiya Sid, list;
>
> it turns out that the 'free' Flowmaster I thought was in inventory has gone
> on to parts unknown; so anyone waiting to hear about the installation, you
> gonna hafta keep waiting;-)
>
> I'll put off the new exhaust for the time being. I would still like to hear
> recommendations about 2" versus 2.25"; as well as muffler placement under
> the floor versus behind the axle. Personal experience is that moving the
> muffler forward (IOW, a longer tailpipe) reduces noise notably, but I don't
> know about performance differences. Also, looking at the U20 from a spec's
> standpoint, it seems like 2.25" would be a better choice than 2".
>
> I too would be interested in knowing the dimensions of the factory 2L tip,
> so a reasonably similar replacement can be fitted. To add to Sid's request -
> a measurement of how far the tip should stick out the back would be helpful.
>
> Thanks gang!
>
> Kyle
> '69 2000, noisy as heck!
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